Nickel-Catalyzed Enantioselective α-Alkenylation of <i>N</i>-Sulfonyl Amines: Modular Access to Chiral α-Branched Amines
作者:Lun Li、Yu-Cheng Liu、Hang Shi
DOI:10.1021/jacs.1c00622
日期:2021.3.24
α-branched amines are common structural motifs in functional materials, pharmaceuticals, and chiral catalysts. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we describe an atom-economical, modular method for a nickel-catalyzed enantioselective α-alkenylation of readily available linear N-sulfonyl amines
established that a cyclopentadienyl RhIII complex with two phenyl groups and a pendant amide moiety catalyzes the formal Lossen rearrangement/[3+2] annulation cascade of N‐pivaloyl benzamides and acrylamides with alkynes leading to substituted indoles and pyrroles. Mechanistic studies revealed that this cascade reaction proceeds via not the Lossen rearrangement to form anilides or enamides but C−H bond cleavage
Stereodivergent Alkyne Hydrofluorination Using Protic Tetrafluoroborates as Tunable Reagents
作者:Rui Guo、Xiaotian Qi、Hengye Xiang、Paul Geaneotes、Ruihan Wang、Peng Liu、Yi‐Ming Wang
DOI:10.1002/anie.202006278
日期:2020.9.14
available precursors remains a synthetic challenge. The metal‐free hydrofluorination of alkynes constitutes an attractive though elusive strategy for their preparation. Introduced here is an inexpensive and easily handled reagent that enables the development of simple and scalable protocols for the regioselective hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These
Rhodium-catalyzed Synthesis of Indenols by Regioselective Coupling of Alkynes with Ortho-carbonylated Arylboronic Acids
作者:Ryo Shintani、Kazuhiro Okamoto、Tamio Hayashi
DOI:10.1246/cl.2005.1294
日期:2005.9
A rhodium/diene-catalyzed regioselective synthesis of indenols has been developed through the coupling of alkynes with ortho-carbonylated arylboronic acids. These reactions proceed under mild conditions in uniformly high yield and regioselectivity. The reaction has also been applied to its asymmetric variant by the use of chiral diene ligands to achieve high enantioselectivity.
of unactivated alkenes using ethanol as the hydrogen source is described. A new NCP-type pincer iridium complex (BQ-NCOP)IrHCl containing a rigid benzoquinoline backbone has been developed for efficient, mild TH of unactivated C-C multiple bonds with ethanol, forming ethyl acetate as the sole byproduct. A wide variety of alkenes, including multisubstituted alkyl alkenes, aryl alkenes, and heteroatom-substituted
描述了使用乙醇作为氢源实现未活化烯烃的转移氢化 (TH) 的第一种通用催化方法。已经开发出一种新的 NCP 型钳形铱络合物 (BQ-NCOP)IrHCl,其含有刚性苯并喹啉主链,可有效、温和地将未活化的 CC 多键与乙醇进行 TH,形成乙酸乙酯作为唯一的副产品。各种烯烃,包括多取代的烷基烯烃、芳基烯烃和杂原子取代的烯烃,以及含 O 或 N 的杂芳烃和内部炔烃,都是合适的底物。重要的是,(BQ-NCOP)Ir/EtOH 系统在反应性官能团(如酮和羧酸)存在下对烯烃氢化表现出高化学选择性。此外,与 C2D5OD 的反应为氘标记化合物提供了一条便捷的途径。详细的动力学和机理研究表明,单取代烯烃(如 1-辛烯、苯乙烯)和多取代烯烃(如环辛烯 (COE))表现出基本的机理差异。乙醇的 OH 基团在苯乙烯反应中显示出正常的动力学同位素效应 (KIE),但在 COE 的情况下显示出显着的反向 KIE。对